Diseases of Amphibians

Abstract

The development and refinement of amphibian medicine comprise an ongoing science that reflects the unique life history of these animals and our growing knowledge of amphibian diseases. Amphibians are notoriously fastidious in terms of captive care requirements, and the majority of diseases of amphibians maintained in captivity will relate directly or indirectly to husbandry and management. Investigators have described many infectious and noninfectious diseases that occur among various species of captive and wild amphibians, and there is considerable overlap in the diseases of captive versus free-ranging populations. In this article, some of the more commonly reported infectious and noninfectious diseases as well as their etiological agents and causative factors are reviewed. Some of the more common amphibian diseases with bacterial etiologies include bacterial dermatosepticemia or "red leg syndrome," flavobacteriosis, mycobacteriosis, and chlamydiosis. The most common viral diseases of amphibians are caused by the ranaviruses, which have an impact on many species of anurans and caudates. Mycotic and mycotic-like organisms cause a number of diseases among amphibians, including chytridiomycosis, zygomycoses, chromomycoses, saprolegniasis, and ichthyophoniasis. Protozoan parasites of amphibians include a variety of amoeba, ciliates, flagellates, and sporozoans Common metazoan parasites include various myxozoans, helminths (particularly trematodes and nematodes), and arthropods. Commonly encountered noninfectious disease etiologies for amphibians include neoplasia, absolute or specific nutritional deficiencies or overloads, chemical toxicities, and inadequate husbandry or environmental management.

Isolation and characterisation of a novel Bohle-like virus from two frog species in the Darwin rural area, Australia

“…Ranaviruses have been isolated from amphibians, fish and reptiles primarily located in North and South America, Europe and SE Asia (Zupanovic et al 1998, Hyatt et al 2000, Fauquet et al 2005, Fox et al 2006, Densmore & Green 2007, Chinchar et al 2009). Virus isolates show serological and genetic relatedness within the genus Ranavirus but are serologically and genetically distinct from members of other genera within the Iridoviridae (Fauquet et al 2005).…”

Tracking viral particles in the intestinal contents of the American bullfrog, Lithobates catesbeianus, by Transmission Electron Microscopy

“…Now, however, viruses are frequently isolated from captive and wild amphibians and many of them are temperature dependent (Densmore and Green, 2007).…”

Ecophysiology meets conservation: understanding the role of disease in amphibian population declines

“…Given the role of multi-host pathogens in emerging infections of both plants and animals, understanding the drivers of disease variation has immediate relevance for human health, economic growth and wildlife conservation [1,8,243]. Because amphibians serve as hosts for a tremendous diversity of micro-and macroparasites, including viruses, helminths, parasitic arthropods, fungi, protists and bacteria [22,23,85], they are ideal for studying disease ecology dynamics. Furthermore, amphibians are declining globally and infectious diseases as well as life-history characteristics are considered important factors in causing or predicting losses [74,178,244], highlighting the importance of identifying factors that predict disease patterns.…”